Ensure lowpan UID can manage LoWPAN interfaces

Bug: b/64399805
Change-Id: Idd0bd7ef0c4de48c95699efc43324bc4dce8e70a
diff --git a/data/etc/platform.xml b/data/etc/platform.xml
index 7e24530..2333fec 100644
--- a/data/etc/platform.xml
+++ b/data/etc/platform.xml
@@ -160,6 +160,9 @@
 
     <assign-permission name="android.permission.ACCESS_SURFACE_FLINGER" uid="graphics" />
 
+    <assign-permission name="android.permission.ACCESS_LOWPAN_STATE" uid="lowpan" />
+    <assign-permission name="android.permission.MANAGE_LOWPAN_INTERFACES" uid="lowpan" />
+
     <!-- This is a list of all the libraries available for application
          code to link against. -->